1. Field of the Invention
The present invention relates to headphones, and in particular, relates to a pressure controlling mechanism for sound-isolating headphones.
2. Description of the Related Art
A sound isolating headphone is known as a personal speaker that is worn on a head with auricles covered therein.
As examples in related art, sound-isolating headphones with configurations disclosed in Patent Documents 1 and 2 are known.
FIG. 6 shows a configuration of a headphone disclosed in Patent Document 1. In FIG. 6, a headphone includes an electro-acoustic transducer formed by combining a yoke B, a magnet C, and a pole piece D which are provided on a base A with a voice coil E1 which is provided at a dome diaphragm E side. The electro-acoustic transducer is disposed at the center of a headphone housing F having an enclosure structure.
A baffle board G is integrally combined with the headphone housing F. An ear pad H is provided on the baffle board G. The baffle board G is facing a front end portion of each voice coil E1 of the electro-acoustic transducer, and a plurality of openings G1 are formed in the baffle board G.
FIG. 7 shows a configuration of a headphone disclosed in Patent Document 2. In FIG. 7, a driver unit (electro-acoustic transducer) P is disposed behind a baffle board K having numerous through holes. A sub-housing L is provided behind the driver unit P, that is, at a rear space side formed by the headphone housing F. An acoustic-resisting member M composed of a buffer material is provided at an opening L1 formed on the sub-housing L.
This configuration improves sound insulation of sound-isolating headphones.
In terms of the sound insulation, for example, an active noise-canceling headphone (not shown) is known that has a microphone therein to detect noise from outside and emits a tone of an opposite phase signal to counter the noise.
[Patent Document 1] Japanese Patent Application Laid-open No. 2003-32768
[Patent Document 2] Japanese Patent Application Laid-open No. 2003-17990